Crusaders weren’t charged with that at all. The inquisition investigated heresy charges and acted as a court. The state punished offenders with jail or capital punishment.
One’s take on the Inquisition depends a great deal on whose history one is reading. Most English speakers’ sources are (not surprisingly) British in origin. Britain was the avowed enemy of Spain and painted the Inquisition and the Catholic Church generally in as dark colors as possible.
Spanish and Latin American histories are less hostile and generally more believable. If one believes them, one learns:
-The objects of the Inquisition were people who would ordinarily have been condemned to death out of hand by the state. Catholic rulers had just taken over the peninsula and had plenty of enemies in-country. Some of those enemies were allied with ferocious Islamic tribes right across the Strait of Gibraltar who might invade at any moment. People who falsified conversion to Catholicism were viewed with total suspicion. Protestants and other heretics were assumed to be allied with Britain and thus, enemies of the state.
-The Inquisition was set up to sort through those who were already condemned by the state to determine who, among them, might be innocent.
-Among other things, the Inquisition provided every accused with a skilled lawyer; something the rest of the world did not do until “Miranda vs. Arizona” in 1966.
-Torture was allowed, but not to a point of being deadly, and not for more than 15 minutes in any session. A doctor was always present to ensure that it didn’t go too far.
-If a person proved he had never faked conversion but remained with his own religion, he was released. If a person who held and expressed heretical beliefs recanted those beliefs publicly, he was released.
-If the inquisitors could not be persuaded of the innocence of the accused or if an accused did not recant, he was transferred back to the state authorities, which typically did what they would have done from the very first, which was execute the individual as a traitor or potential traitor to the state.
-The Inquisition was nearly forced on the Spanish state by the Church. Left to its own devices, the kingdom and the populace would have tried less and killed more.
-The Inquisition was harsher in Spain than anywhere else. While it existed in Latin America, not a single person who went through the Inquisition was killed. Some historians have estimated that the number killed who went through the Inquisition in Spain was about 1200.
-A lot of what is attributed to the Inquisition was not the Inquisition. There were other tribunals in Spain at the time; secular tribunals, who were more intent on killing potential enemies than in saving the innocent.
Historians say Inquisition wasn't that bad | World news | The Guardian.